Computer-aided Design of 30 kW Horizontal Axis Wind Turbine Blades

Abstract

Blade geometry optimization for 30 kW wind turbine with 6.5 tip speed ratio is applied via Betz and Schmitz formulas, using “QBlade” software. These formulas were applied to modify chord distribution and twist angle of airfoil SD7062. Using the same software, 3D model of blades and rotors for both cases are generated. Afterwards, BEM simulation is conducted in the “QBlade” for both cases and values of power coefficient depending on tip speed ratio, as well as power output depending on wind speed for both optimised wind turbines is obtained. These values for both cases are used to determine annual energy production, while using Weibull distribution to determine probability for certain wind speeds to occur. Shape (k) and scale (c) parameters were identical in both simulations. After conducted simulations, it is noted that Betz optimised rotor has higher peek for power production, compared to the Schmitz optimised rotor. Also, both rotors have slightly different power coefficients depending on tip speed ratio. Using Weibull equations, it is estimated that Betz optimised rotor has 2.79% higher annual energy production, compared to the Schmitz optimised rotor.